What is CVE-2026-23736?

CVE-2026-23736 is a high-severity vulnerability in Lxsmnsyc Seroval, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.3/10. Published 2026-01-21.

How severe is CVE-2026-23736?

High severity. CVSS v3 base score is 7.3 out of 10.

Prototype Pollution in Lxsmnsyc Seroval

CVE-2026-23736

seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, due to improper input validation, a malicious object key can lead to prototype pollution during JSON deserialization. This vulnerability affects only JSON deserialization functionality. This issue is fixed in version 1.4.1.

Vulnerability class: Prototype Pollution

EPSS: 0.002 (16.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

Affected products

Lxsmnsyc Seroval — versions < 1.4.1

Weakness classification (CWE)

CWE-1321 — Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution)

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-23736?: CVE-2026-23736 is a high-severity vulnerability in Lxsmnsyc Seroval, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.3/10. Published 2026-01-21.
How severe is CVE-2026-23736?: High severity. CVSS v3 base score is 7.3 out of 10.